National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

San Marcos, San Marcos Municipal Airport (KHYI)

Lat: 29.89°NLon: 97.86°WElev: 597ft.

Mostly Cloudy

81°F

27°C

Humidity 61%
Wind Speed SE 14 mph
Barometer 30.05 in (1016.9 mb)
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 11 Apr 4:56 pm CDT
Extended Forecast for

4 Miles SW San Marcos TX

  • This Afternoon

    This Afternoon: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 81. Southeast wind around 10 mph, with gusts as high as 20 mph.

    High: 81 °F

    Chance
    T-storms

  • Tonight

    Tonight: A chance of showers and thunderstorms. Patchy fog after 4am. Otherwise, mostly cloudy, with a low around 68. Southeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 68 °F

    Chance
    T-storms then
    Chance
    Showers and
    Patchy Fog

  • Sunday

    Sunday: Showers likely and possibly a thunderstorm before 1pm, then showers and thunderstorms likely after 1pm. Some of the storms could be severe. Patchy fog before 11am. Otherwise, cloudy, with a high near 77. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 70%. New rainfall amounts between three quarters and one inch possible.

    High: 77 °F

    Severe
    Thunderstorms
    and Patchy
    Fog

  • Sunday Night

    Sunday Night: A 50 percent chance of showers and thunderstorms, mainly before 1am. Cloudy, with a low around 68. South wind around 10 mph, with gusts as high as 20 mph.

    Low: 68 °F

    Chance
    T-storms

  • Monday

    Monday: A 20 percent chance of showers and thunderstorms after 1pm. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 83. South wind around 10 mph, with gusts as high as 20 mph.

    High: 83 °F

    Patchy Fog
    then Slight
    Chance
    T-storms

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 68. South southeast wind around 10 mph, with gusts as high as 20 mph.

    Low: 68 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 82. South wind 10 to 15 mph, with gusts as high as 25 mph.

    High: 82 °F

    Cloudy then
    Slight Chance
    T-storms

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 67. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.

    Low: 67 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: A 30 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 84. South wind around 10 mph, with gusts as high as 20 mph.

    High: 84 °F

    Mostly Cloudy
    then Chance
    T-storms

Detailed Forecast

This Afternoon
A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 81. Southeast wind around 10 mph, with gusts as high as 20 mph.
Tonight
A chance of showers and thunderstorms. Patchy fog after 4am. Otherwise, mostly cloudy, with a low around 68. Southeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Sunday
Showers likely and possibly a thunderstorm before 1pm, then showers and thunderstorms likely after 1pm. Some of the storms could be severe. Patchy fog before 11am. Otherwise, cloudy, with a high near 77. South southeast wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 70%. New rainfall amounts between three quarters and one inch possible.
Sunday Night
A 50 percent chance of showers and thunderstorms, mainly before 1am. Cloudy, with a low around 68. South wind around 10 mph, with gusts as high as 20 mph.
Monday
A 20 percent chance of showers and thunderstorms after 1pm. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 83. South wind around 10 mph, with gusts as high as 20 mph.
Monday Night
Mostly cloudy, with a low around 68. South southeast wind around 10 mph, with gusts as high as 20 mph.
Tuesday
A 20 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 82. South wind 10 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
Mostly cloudy, with a low around 67. South southeast wind 10 to 15 mph, with gusts as high as 20 mph.
Wednesday
A 30 percent chance of showers and thunderstorms after 1pm. Mostly cloudy, with a high near 84. South wind around 10 mph, with gusts as high as 20 mph.
Wednesday Night
A 20 percent chance of showers and thunderstorms before 1am. Mostly cloudy, with a low around 68.
Thursday
Partly sunny, with a high near 88.
Thursday Night
Mostly cloudy, with a low around 68.
Friday
Mostly cloudy, with a high near 88.
Friday Night
Mostly cloudy, with a low around 69.
Saturday
A chance of showers and thunderstorms. Mostly cloudy, with a high near 85.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
4 Miles SW San Marcos TX
 29.86°N 97.99°W (Elev. 748 ft)
Last Update:
5:32 pm CDT Apr 11, 2026
Forecast Valid:
5pm CDT Apr 11, 2026-6pm CDT Apr 18, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation